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A key will be included in the multipart array (the first shown), generally starting with ‘temporary-uploads/…’. This will represent the ‘path’ when referring to this uploaded file in subsequent requests - eg. to attach the file to a new document, or use it as an ID photo for a person in the system.
AWS provides more information on this concept here; https://docs.aws.amazon.com/AmazonS3/latest/dev/PresignedUrlUploadObject.html